Engine system for increasing available turbocharger energy

Abstract

An engine system for a machine is disclosed. The engine system may have an intake manifold configured to direct air into a donor cylinder and a non-donor cylinder of an engine. The engine system may also have a first exhaust manifold configured to direct exhaust from the non-donor cylinder to the atmosphere. The engine system may also have a second exhaust manifold configured to receive exhaust from the donor cylinder. The engine system may further have a control valve configured to selectively direct a first amount of exhaust from the second exhaust manifold to the intake manifold. In addition, the engine system may have an orifice configured to allow a second amount of exhaust to flow from the second exhaust manifold to the first exhaust manifold.

What is claimed is: 
     
       1. An engine system, comprising:
 a first intake manifold configured to direct air into a first donor cylinder and a first non-donor cylinder of an engine; 
 a second intake manifold configured to direct the air into a second donor cylinder and a second non-donor cylinder of the engine; 
 a first exhaust manifold configured to direct exhaust from the first non-donor cylinder to the atmosphere; 
 a second exhaust manifold configured to receive exhaust from the first donor cylinder; 
 a third exhaust manifold configured to direct exhaust from the second non-donor cylinder to the atmosphere; 
 a fourth exhaust manifold configured to receive exhaust from the second donor cylinder; 
 a first control valve configured to selectively direct a first amount of exhaust from the second exhaust manifold to the first intake manifold; 
 a second control valve configured to selectively direct a third amount of exhaust from the fourth exhaust manifold to the second intake manifold; and 
 an orifice configured to allow a second amount of exhaust to flow from the second exhaust manifold to the first exhaust manifold. 
 
     
     
       2. The engine system of  claim 1 , further including a cooler configured to cool the air and direct the cool air to the first intake manifold. 
     
     
       3. The engine system of  claim 2 , wherein the cooler is further configured to:
 cool the first amount of exhaust, and 
 direct a mixture of the cool air and the first amount of exhaust to the first intake manifold. 
 
     
     
       4. The engine system of  claim 3 , wherein:
 the first control valve is configured to selectively direct the first amount of exhaust from the second and fourth exhaust manifolds to the first intake manifold; and 
 the second control valve is configured to selectively direct the third amount of exhaust from the second and fourth exhaust manifolds to the second intake manifold. 
 
     
     
       5. The engine system of  claim 3 , wherein the orifice is a first orifice, and the engine system further includes a second orifice configured to allow a fourth amount of exhaust to flow from the fourth exhaust manifold to the third exhaust manifold. 
     
     
       6. The engine system of  claim 5 , wherein:
 the first orifice has a first variable area; 
 the second orifice has a second variable area; and 
 the engine system further includes a controller configured to selectively adjust the first and second variable areas to control the second and fourth amounts of exhaust. 
 
     
     
       7. The engine system of  claim 6 , wherein the controller is in communication with the first and second control valves and is configured to selectively adjust the first amount of exhaust and the third amount of exhaust. 
     
     
       8. The engine system of  claim 7 , wherein the first amount of exhaust and the third amount of exhaust are equal. 
     
     
       9. The engine system of  claim 8 , further including:
 a diesel particulate filter configured to filter the first and third amounts of exhaust; and 
 a diesel oxidation catalyst disposed upstream of the diesel particulate filter. 
 
     
     
       10. The engine system of  claim 9 , wherein the diesel particulate filter is a first diesel particulate filter, the diesel oxidation catalyst is a first diesel oxidation catalyst, and the engine system further includes:
 a second diesel particulate filter configured to filter the second and fourth amounts of exhaust before being discharged to the atmosphere; and 
 a second diesel oxidation catalyst disposed upstream of the second diesel particulate filter. 
 
     
     
       11. A method of operating an engine, comprising:
 directing air through a first intake manifold into a first donor cylinder and a first non-donor cylinder of the engine; 
 directing exhaust from the first non-donor cylinder through a first exhaust manifold to the atmosphere; 
 directing exhaust from the first donor cylinder to a second exhaust manifold; 
 selectively directing a first amount of exhaust from the second exhaust manifold to the first intake manifold; 
 directing a second amount of exhaust from the second exhaust manifold through an orifice to the first exhaust manifold; 
 directing the air into a second donor cylinder and a second non-donor cylinder of the engine through a second intake manifold; 
 directing exhaust from the second non-donor cylinder through a third exhaust manifold to the atmosphere; 
 directing exhaust from the second donor cylinder to a fourth exhaust manifold; 
 selectively directing a third amount of exhaust from the fourth exhaust manifold to the second intake manifold; and 
 directing a fourth amount of exhaust from the fourth exhaust manifold to the third exhaust manifold. 
 
     
     
       12. The method of  claim 11 , further including:
 cooling air using a cooler; and 
 directing the cooled air to the first intake manifold. 
 
     
     
       13. The method of  claim 12 , wherein the first amount of exhaust is equal to the third amount of exhaust. 
     
     
       14. The method of  claim 11 , further including:
 determining an amount of an exhaust gas component in the exhaust from the first non-donor cylinder; and 
 increasing the first amount of exhaust when the amount of the exhaust gas component is different from a predetermined value. 
 
     
     
       15. The method of  claim 14 , further including filtering the first amount of exhaust before directing the first amount of exhaust to the first intake manifold. 
     
     
       16. The method of  claim 15 , further including filtering the second amount of exhaust before discharging the second amount of exhaust into the atmosphere. 
     
     
       17. An engine, comprising:
 a first cylinder bank including a first donor cylinder and a first non-donor cylinder; 
 a second cylinder bank including a second donor cylinder and a second non-donor cylinder; 
 a first intake manifold connected between the atmosphere and the first cylinder bank; 
 a second intake manifold connected between the atmosphere and the second cylinder bank; 
 a first exhaust manifold fluidly connected to the first non-donor cylinder; 
 a second exhaust manifold fluidly connected to the first donor cylinder; 
 a third exhaust manifold fluidly connected to the second non-donor cylinder; 
 a fourth exhaust manifold fluidly connected to the second donor cylinder; 
 a first control valve associated with the second exhaust manifold and selectively movable to allow a first amount of exhaust to pass from the second exhaust manifold into the first intake manifold; 
 a first orifice to allow a second amount of exhaust to flow between the second exhaust manifold and the first exhaust manifold; 
 a second control valve associated with the second exhaust manifold and selectively movable to allow a third amount of exhaust to pass from the fourth exhaust manifold into the second intake manifold; 
 a second orifice to allow a fourth amount of exhaust to flow between the forth exhaust manifold and the third exhaust manifold; and 
 a controller configured to selectively control the first and second control valves. 
 
     
     
       18. The engine of  claim 17 , wherein the first intake manifold includes:
 a first section configured to direct air to the first donor cylinder; and 
 a second section configured to direct the air to the first non-donor cylinder. 
 
     
     
       19. The engine of  claim 17 , wherein the first intake manifold includes:
 a first section configured to direct a first concentration of exhaust into the first donor cylinder; and 
 a second section configured to direct a second concentration of exhaust into the first non-donor cylinder. 
 
     
     
       20. The engine of  claim 19 , further including:
 a cooler configured to cool the air and direct the first portion of the cool air to the first section and the second portion of the cool air to the second section; 
 a third control valve configured to direct the donor cylinder portion of the first amount of exhaust to the first section and the non-donor cylinder portion of the first amount of exhaust to the second section.